Hi John,
Currently there isn't a setting to allow an Admin to set a Calendar view to start at 7 AM instead of 12 AM to restrict access like that. It is possible to use our recently introduced Data Rules to put restrictions in place to prevent users from saving data that doesn't fit the right criteria.
https://help.quickbase.com/user-assistance/1/validation.htmlThese rules can allow you to guide users by putting limits in place on what kind of data can be entered and is built off the Quick Base formulas to be fairly flexible in how it can be applied. You are even able to set the message that will pop up for a user when they try to save a record that doesn't fall inside the rules you create.
Alternatively, if being able to set this directly in the Calendar report would be helpful for your business needs I would suggest submitting it to our User Voice. User Voice is the tool our product developers use to help collect customer feedback on new features and enhancements to existing features. The Quick Base User voice can most easily be accessed from the My Apps page in Quick Base by clicking on the orange Feedback tab that appears on the right of the page or at
http://quickbase.uservoice.com by signing in with your Quick Base credentials. If you do create a User Voice request I would suggest posting a link to it back here on the Community so that other Community members with a similar need to can show their support as well. I hope that information is helpful.